I think they run better in a bigger wheel too
I guess hamsters are different shapes and sizes as well as weights. I noticed when Charlie runs in a wheel that isn't quite big enough, his back is straight but his head is up at an angle. If you mean this flying saucer - I had it and it's good for a Syrian. Nice and quiet too. I wouldn't have it as a main wheel but it's a nice extra.
https://www.amazon.co.uk/Trixie-Runn...s=Running+disc